Geometric Dimensioning and Tolerancing

Chapter 6, Form, Orientation, Profile, and Runout Tolerances

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Straightness

• Straightness can be applied to a surface (either flat or cylindrical).

• Straightness can also be applied to an axis.

straightness applied to aflat surface

straightness applied to acylindrical surface

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Straightness

As you measure along a line, the height must be between 12 and 13 mm and the variation may not be more than 0.5 mm from a straight line.

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Straightness

• Straightness applied to a cylindrical surface.

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Straightness

• Straightness can also be applied to an axis.

12.50.2

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Flatness

• Flatness is the condition of a surface where all elements are in one plane.

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Flatness

• The surface could be checked by translating the part under a dial indicator.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Circularity

• Circularity is roundness.• At any cross-sectional measurement during one

complete revolution of the feature, all points of the surface are perpendicular at an equal distance from a common axis.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Cylindricity

• Cylindricity is the condition of an entire feature surface during one revolution in which all surface points are an equal distance from a common axis.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Perpendicularity

• Perpendicularity is the condition of an entire surface, plane, or axis at a right angle to a datum plane or axis.

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Perpendicularity

• Perpendicularity is the condition of an entire surface, plane, or axis at a right angle to a datum plane or axis.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Angularity

• Angularity is the condition of an axis or plane other than 90 degrees to another datum plane or axis.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Parallelism

• Parallelism is the condition of a surface, center plane, or axis that is an equal distance at all points from a datum plane or axis.

bilateral tolerance zone

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Parallelism

• Example of a cylinder being parallel to another surface.

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Parallelism

• Example of a cylinder being parallel to another cylinder.

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Profile: line , surface

• Profile tolerance is specified for designs where the surface is to be controlled within a given basic shape.

• Specified for irregular features that are difficult to control with other form or orientation tolerances.

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Profile: line , surface

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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Circular Runout and Total Runout

• The worst circular runout occurs at the slice with the greatest variation (0.03 mm in this case).

• Total runout is the difference between the highest and lowest readings found over the entire feature. (0.11 mm in this case).

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Circularity vs. Runout

• Can anyone explain the difference between the two and can they be used on a print interchangeabilty?

• http://www.eng-tips.com/viewthread.cfm?qid=186399• tp://communities.ptc.com/message/173195

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Circularity vs. Runout

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Geometric CharacteristicsForm, Orientation, Profile, and Runout Tolerances

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